Bolt Catch

ABSTRACT

A bolt catch includes an outer member and a body member. The body member includes a void where a biasing member is positioned therein. The body member is normally biased upward and thus blocks the bolt from moving forward and engaging a cartridge from a magazine. The user is required to engage the bolt catch in order to move the bolt forward and load the chamber with a round or cartridge. Thus, the bolt catch converts a semi-automatic firearm into a bolt action firearm.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 62/583,581, filed on Nov. 9, 2017, which is incorporated by reference in its entirety.

FIELD

The present disclosure relates to firearm accessories and in particular to a bolt catch, bolt stop or bolt release.

BACKGROUND

Firearms have been used for several centuries for various purposes including as weapons for warfare, law enforcement, self defense, hunting and target practice. Although many new weapons and weapon systems have been developed, firearms are still widely used by soldiers and law enforcement but also by civilians for recreational use. Over time, firearms have been improved in many ways, but opportunities for improvement still exist in particular areas and for particular aspects of these devices.

Firearms have been constructed with a magazine that holds ammunition for the firearm. Magazines have been used that can be changed out quickly when one magazine is empty, speeding up the process of reloading the firearm. Magazines have been attached to the remainder of the firearm with a latch or catch, and a release mechanism, such as a button or lever, to release the catch and thereby release the magazine, for instance, so a full magazine can be installed in its place.

In addition, firearms have been constructed with a bolt catch that retains the bolt or carrier in an aft or pulled position when the last round in the magazine is fired. The bolt catch allows the operator to change the magazine, release the bolt catch, and continue firing, without charging the weapon (e.g., pulling the charging handle). In this manner, the bolt catch makes it easier and quicker to reload the firearm. In a number of firearms, the bolt catch can also be used to hold the bolt or carrier back or open for other purposes, for example, to clear a jam or malfunction within the weapon, or to inspect the chamber.

As shown in FIGS. 1-6, bolt catches 20 have been made with a lever 32 that pivots about a point of rotation 28 and that have a bolt release pad 24 that an operator presses (e.g., with a thumb or finger) to release the bolt. In a number of firearms, the lever 32 also has a bolt engagement pad or feature 26 that the operator can press while the bolt is retracted to engage the bolt catch 20 and hold the bolt or carrier back, e.g., when the magazine is not engaged. Typically, the bolt release pad 24 and the bolt engagement pad 26 are located on the same side of the firearm and are activated or operated by the user by pressing the appropriate pad or feature to release the bolt or engage the catch.

In many typical firearm designs, a magazine is used to store and feed ammunition into a firing chamber. In many manual as well as semi and fully automatic firearms, a bolt moves backward and forward between each shot, propelled by recoil or expanding gas or a recoil spring. When the bolt moves forward, it moves a cartridge from the magazine and pushes it into the chamber, as shown in FIGS. 4 (right) and 5. During firing, the bolt blocks and seals the chamber. When the bolt moves back, the spent ammunition casing is removed from the chamber and ejected from the firearm. Typically, after the last round in the magazine is fired, a floor plate of the magazine is pushed upward by spring action to contact and lift a bolt “stop” or “catch” that is mounted within the firearm receiver, as shown in FIGS. 4 (left) and 6. In this lifted position, the bolt stop holds the bolt rearward of the magazine to allow viewing of the chamber and for other purposes. After an empty magazine is removed and a full magazine inserted into the firearm, the bolt must be allowed to move forward to chamber a new round of ammunition.

Various rifles known by the designations “M16” or “M4” or “AR15” include a bolt stop that operates in the above manner. These rifles include a bolt stop that is pivotably secured within the rifle receiver and is rotated upward to block forward travel of the rifle bolt as discussed above. Bolt catches in semi-automatic firearms are configured to be continuously disengaged so that the bolt is free to engage cartridge after cartridge without human intervention. The bolt catch is engaged and the bolt is prevented from engaging another cartridge only when the magazine is empty. After a new full magazine is inserted, the bolt stop is manually rotated downward to then again allow the bolt to move forward under spring biasing to chamber continuous rounds from the magazine.

The Second Amendment of the U.S. Constitution provides “the right of people to keep and bear Arms.” However, the Second Amendment is not without regulation. With the increase in gun violence, over the years States have enacted laws banning or limiting the possession, use and manufacture of semi-automatic firearms.

As discussed above, the semi-automatic feature in firearms is generally accomplished by allowing the bolt to be automatically cycled after each round fired. That is, the bolt catch (also known as a bolt stop or bolt release) is in a downward or disengaged state as long as additional rounds or cartridges are present in the magazine and thus, subsequent rounds are positioned for firing and the bolt of the firearm is able to travel above the rested bolt catch to engage with the next round for immediately firing without further human intervention. This is shown for example in FIGS. 4 (right) and 5.

To abide by the laws of certain States, semi-automatic firearms have been modified to act as bolt action firearms. A semi-automatic firearm is defined as a firearm where energy from a fired round extracts the expended cartridge and loads a new cartridge leaving the gun in a ready to fire state. In order to qualify as a bolt action firearm, that energy can extract a spent cartridge but cannot load a new one. One way to accomplish this is to modify the firearm by installing a bolt catch that is able to halt the bolt from loading a new cartridge leaving the gun in a ready to fire state, so that the bolt is not automatically replaced after each round fired. This is shown in FIGS. 4 (left) and 6. Instead, the user must physically engage the bolt catch to move the bolt forward to load a new cartridge and leave the gun in a ready to fire state.

Modified bolt catches exist in the prior art. However, prior art bolt catches suffer from numerous deficiencies. In one example, the firearm must be drastically altered to install the new bolt catch. This requires much labor and therefore much cost. It is also undesirable to machine the firearm, especially if it is to the outer parts of the firearm, because such changes are permanent and the user may not wish to show the alterations in the event the user decides to return the firearm to its original form.

In another example, the modified bolt catch includes components that are exposed and therefore there is a risk of failure due to lack of stability. Such failure could affect the performance of the firearm and even more serious, could be a safety hazard.

Therefore, a need exists for a bolt catch that is easily and securely installed to an existing semi-automatic firearm for converting it to a bolt action firearm.

SUMMARY

The following presents a simplified summary of some embodiments of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description that is presented later.

The present invention in general pertains to mechanisms in firearms that control or limit the movement of the firearm “bolt” element. The bolt catch of the present invention solves the problems of the prior art and provides additional advantages. In general, the bolt catch includes an outer member and a body member. The body member includes a void where a biasing member is positioned therein. The body member is normally biased upward and thus blocks the bolt from moving forward and engaging a cartridge from a magazine. The user is required to engage the bolt catch in order to move the bolt forward and load the chamber with a round or cartridge. Thus, the bolt catch of the present invention provides a means to convert a semi-automatic firearm into a bolt action firearm.

In one embodiment, the bolt catch is used with a firearm having a bolt and a slot with a floor, and the bolt catch comprises: a body member dimensioned to be disposed within the slot, the body member having a pivot portion, wherein the body member is biased to rotate within the slot about the pivot portion, thereby blocking the bolt from moving in a predetermined direction. The pivot portion includes a hole for receiving a pivot pin. The bolt catch may include an outer member extending perpendicular to a longitudinal length of the body member, the outer member including a finger pad. The body member includes: a void; and a biasing member disposed in the void; wherein the body member is biased by the biasing member. The biasing member has a pair of ends, with one end engaging the floor of the slot, and the other end engaging the body member. The void includes a plurality of voids; and wherein the biasing member includes a plurality of biasing members, with each biasing member disposed in a respective void. The void has a rounded edge to prevent the biasing member from binding to the body member. The biasing member is selected from a compression spring, a torsion spring, and a magnet.

In another embodiment, a bolt catch is used with a firearm having a bolt, a slot with a floor, and a magazine for holding a cartridge, and the bolt catch comprises: a body member dimensioned to be disposed within the slot, the body member having a pivot portion, wherein the body member is biased to rotate in a first rotational direction within the slot about the pivot portion, thereby blocking the bolt from moving forward; and an outer member extending perpendicular to a longitudinal length of the body member, the outer member including a finger pad for a user to press for rotating the body member in a second rotational direction opposite the first rotational direction and for countering the restorative force of the resilient member, thereby moving the bolt forward to engage the cartridge. The pivot portion includes a hole for receiving a pivot pin. The body member includes: a void; and a biasing member disposed in the void; wherein the body member is biased by the biasing member. The biasing member has a pair of ends, with one end engaging the floor of the slot, and the other end engaging the body member. The void includes a plurality of voids; and wherein the biasing member includes a plurality of biasing members, with each biasing member disposed in a respective void. The void has a rounded edge to prevent the biasing member from binding to the body member. The biasing member is selected from a compression spring, a torsion spring, and a magnet.

In a further embodiment, a method converts a semi-automatic firearm into a bolt action firearm, the semi-automatic firearm having a bolt, a slot with a floor, and a magazine for holding a cartridge, and the method comprises: providing a bolt catch having a body member and an outer member extending perpendicular to a longitudinal length of the body member, the outer member including a finger pad, the body member dimensioned to be disposed within the slot, the body member having a pivot portion; positioning the body member within the slot; biasing the body member to rotate in a first rotational direction within the slot about the pivot portion, thereby blocking the bolt from moving forward; and pressing the finger pad to rotate the body member in a second rotational direction opposite the first rotational direction for countering the restorative force of the resilient member, thereby moving the bolt forward to engage the cartridge. The body member includes: a void; and a biasing member disposed in the void; wherein the body member is biased by the biasing member. The biasing member has a pair of ends, with one end engaging the floor of the slot, and the other end engaging the body member. The void includes a plurality of voids; and wherein the biasing member includes a plurality of biasing members, with each biasing member disposed in a respective void. The biasing member is selected from a compression spring, a torsion spring, and a magnet.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing summary, as well as the following detailed description of presently preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In addition, some of the figures are provided further details including exemplary dimensions which are in units of inches.

In the drawings:

FIG. 1 is a side perspective view of a stock bolt catch of the prior art, specifically for an AR-15 semi-automatic rifle;

FIG. 2 is a top view of the bolt catch of FIG. 1;

FIG. 3 is a side view of the bolt catch of FIG. 1;

FIG. 4 are top views of a lower receiver of a firearm as an illustration of a prior art bolt catch such as that shown in FIG. 1 in an engaged state (left) and a disengaged state (right);

FIG. 5 is a sectional view of a lower receiver of a firearm showing a prior art bolt catch and bolt in a disengaged state for purposes of illustrating the function of a bolt catch;

FIG. 6 is a sectional view of a lower receiver of a firearm showing a prior art bolt catch and bolt in an engaged state for purposes of illustrating the function of a bolt catch;

FIG. 7 is a side perspective view of a lower receiver of a firearm, specifically an AR-15 semi-automatic rifle, without internal components;

FIG. 8 is a top view of a lower receiver of the firearm of FIG. 7 without internal components;

FIG. 9 is a side perspective view of an embodiment of a bolt catch of the present invention;

FIG. 10 is a side view of the bolt catch of FIG. 9;

FIG. 11 is an illustration of a side view of another embodiment of a bolt catch of the present invention; and

FIG. 12 is an illustration of a side view of an alternative embodiment of a bolt catch of the present invention.

To facilitate an understanding of the invention, identical reference numerals have been used, when appropriate, to designate the same or similar elements that are common to the figures. Further, unless stated otherwise, the features shown in the figures are not drawn to scale, but are shown for illustrative purposes only.

DETAILED DESCRIPTION

Certain terminology is used in the following description for convenience only and is not limiting. The article “a” is intended to include one or more items, and where only one item is intended the term “one” or similar language is used. Additionally, to assist in the description of the present invention, words such as top, bottom, side, upper, lower, front, rear, inner, outer, right and left are used to describe the accompanying figures. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.

The operation of the conventional bolt stop and its release function in semi-automatic rifles is well known and understood. While the rifle bolt is held back by a bolt stop, to allow the bolt to move forward the bolt stop must be rotated downward about a pivot pin and against the bias of a spring.

In the present invention, the bolt stop is modified to enable the present invention, or an inventive replacement bolt stop is provided and assembled with the rifle in place of the original bolt stop. Either method will provide the same result and enable the inventive objectives and functions.

Referring to FIGS. 7 and 8, a lower receiver 10 of a firearm, specifically an AR-15 rifle, is shown. The lower receiver 10 includes a slot 12 extending downward and partially across the width of an upper section of the lower receiver 10. The slot 12 is formed by a slot floor 13 and a plurality of slot walls 15 extending upwardly therefrom. A spring aperture 14 extends partially across the width of the upper section of the lower receiver 10 below the slot 12. A rod housing 16 extends outwardly from the lower receiver 10 and positioned such that the rod housing 16 is substantially aligned with the slot 12 along the length of the lower receiver 10. Each component of the rod housing 16 includes holes which are aligned to each other to form a pivoting axis parallel to the length of the firearm.

Referring to FIGS. 1-3, a stock bolt catch 20 for an AR-15 rifle is shown. The stock bolt catch 20 includes a substantially vertical outer member 22. The outer member 22 includes a finger pad 24 positioned at an upper section thereof. A lower section includes a protrusion 26 extending outwardly and an inner surface 27. A pivot aperture 28 extends through the outer member 22 intermediate the upper and lower sections. The stock bolt catch 20 also includes a body member 30 extending inward from the outer member 22, substantially perpendicular therefrom. The body member 30 includes a body 32 and an engagement member 34 extending substantially perpendicular from an upper section thereof. The engagement member 34 includes an engaging protrusion 36 for engaging a magazine.

Referring to FIGS. 4-8, the stock bolt catch 20 is installed on the firearm by inserting a biasing member (not shown) into the spring aperture 14. The inner surface 27 engages the biasing member and the stock bolt catch 20 is fixed to the rod housing 16 with a rod or fixing member (not shown) extending through the pivot aperture 28 and the rod housing 16. In this configuration, the lower section of the stock bolt catch 20 is normally biased outward, as shown in FIGS. 4 (right) and 5, such that a bolt of the firearm is continuously engageable with a cartridge or round of a magazine 40. However, when the magazine 40 is empty, a floor plate 42 of the magazine 40 is moved upward and engages the engagement member 34, compressing the biasing member and moving the finger pad 24 outward, as shown in FIGS. 4 (left) and 6. In this configuration, the body member 30 moves upward and engages the bolt 50, preventing the bolt 50 from engaging the cartridge or round, as shown for example in FIG. 6.

A typical semi-automatic firearm is constructed in this manner described above. That is, the stock bolt catch 20 is configured such that the bolt is free to move forward so long as the magazine has cartridges available for loading.

Referring now to FIGS. 9 and 10, an embodiment of a bolt catch 120 of the present invention is shown. The bolt catch 120 includes a substantially vertical outer member 122 having an upper section and a lower section. The outer member 122 includes a finger pad 124 positioned at an outer surface of the upper section thereof. A pivot aperture 128 extends through the outer member 122 intermediate the upper and lower sections substantially perpendicular to the finger pad 124.

The bolt catch 120 also includes a body member 130 extending inward from the outer member 122, substantially perpendicular therefrom. The body member 130 is sized substantially similar to the slot 12, shown in FIGS. 7-8, with minimal tolerance so that the body member 130 is secured therein to limit transverse movement and so that the body member 130 is also free to pivot upward and downward within the slot 12. The body member 130 includes a body 132 and an engagement member 134 extending substantially perpendicular from an upper section thereof. The engagement member 134 includes an engaging protrusion 136 for engaging a magazine.

A portion of the body member 132 includes a void 138 partially extending therethrough. The void 138 is formed with radiused edges 139 at a bottom portion of the body 132, as shown in FIGS. 9 and 10. Because the biasing member to be inserted into the void 138 is linear and the body 132 is moving non-linearly, i.e., pivoting about the pivot aperture 128, the rounded edges 139 prevent the biasing member from binding to the body 132. Moreover, the configuration of the void 139 provides the desired function of the bolt catch 120 while preventing debris from affecting the performance of the bolt catch 120.

Referring to FIGS. 7-10, the bolt catch 120 is installed on a lower receiver 10 of the firearm by securing a biasing member (not shown) into the void 138 and inserting the body member 130 into the slot 12. In this position, the biasing member is engaged with the slot floor 13 on one end and engaged with an upper surface of the void on the body member 130 on an opposing end. In this embodiment, the biasing member is a conventional spring. However, the biasing member could be a torsion spring or magnets.

A rod or fixing member (not shown) is extended through the pivot aperture 128 and the bolt catch 120 is pivotably fixed to the rod housing 16 via the holes on the rod housing 16. In this configuration, the body member 130 of the bolt catch 120 is normally biased upward, such that the body member 130 is in front of the bolt regardless of whether the magazine is full or empty, thus preventing the bolt from engaging the cartridge or round. In other words, to load each cartridge, the user is required to press the finger pad 124 inward so that the body member 130 is moved downward and the bolt is able to move forward to engage the cartridge from the magazine to load a new cartridge, leaving the gun in a ready to fire state. As such, the biasing member is compressed until the cartridge is spent and the bolt moves backward, at which time the body member 130 moves upward and blocks the bolt from engaging the next cartridge.

Referring to FIG. 11, in another embodiment of a bolt catch 220 of the present invention, the body member 130 includes two voids 138 for receiving respective biasing members 140, such as compression springs. In this configuration, the upward biasing force could be increased by using more than one biasing member 140. As such, it is further ensured that the body member 130 will return to its normally upward position so that the bolt is prevented from engaging the next cartridge for loading a new cartridge after a round is fired.

In yet another embodiment shown in FIG. 12, the bolt catch 320 of the present invention described above is manufactured without voids in the body member 142. Instead, an aperture is machined and formed in the slot floor 13 at or about an inner portion 17 (see FIG. 8). A biasing member is secured within the aperture and is engaged with the aperture on one end and a lower surface of the body member 130 on an opposing end. In this configuration, minimal modification is necessary to the firearm to accomplish a bolt action firearm.

The various components of the outer member 122 and the body member 130 are all integral and rigidly coextensive. While the various components of the outer member 122 and body member 130 are described here distinctly, this is only for convenience and each of the elements have no inherent boundary and they exist and operate as a single integrated whole. The particular details of the shape of the components of the bolt catch 120, 220 are not critical but may be altered somewhat to satisfy particular user desires.

The integrated whole of the bolt catch of the present invention is preferably cast or machined from a single piece of steel of the same specification as a conventional bolt stop. For example, the bolt catch of the present invention could be manufactured with a number of high-strength materials such as stainless steel, 4140 high tensile steel, B7 alloy steel and titanium. One of ordinary skill in the art will recognize that other materials could be used as well.

With the bolt catch of the present invention, any gas piston or gas impingement operated semi-automatic firearm could be modified into an assisted bolt action rifle while replacing only one component. The present invention provides a push button action that is easy to install and use, especially for the handicapped. Moreover, the firearm could also be easily converted back to the original semi-automatic function by replacing the bolt catch of the present invention with the stock bolt catch.

In the embodiments illustrated in the figures, the bolt catch of the present invention can be used on AR-15 rifles as well as any other automatic and semi-automatic firearms. For the purposes of this disclosure, the term “firearm” generally refers to said rifles as well as similar rifles and other variants. One example variant of the AR-15 rifle is the M-16. Still other variants that are known now or are developed later are intended to be included within the scope of the term “firearm,” as understood by a person of skill in the art.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention will be, therefore, indicated by claims rather than by the foregoing description. All changes, which come within the meaning and range of equivalency of the claims, are to be embraced within their scope. 

1. A bolt catch for a firearm having a bolt and a slot with a floor, the bolt catch comprising: a body member dimensioned to be disposed within the slot, the body member having: a pair of opposing planar walls and a top planar wall, with the planar walls forming a parallelepiped-shaped void in the body member; and a pivot portion, wherein the body member is biased to rotate within the slot about the pivot portion, thereby blocking the bolt from moving in a predetermined direction.
 2. The bolt catch of claim 1, wherein the pivot portion includes a hole for receiving a pivot pin.
 3. The bolt catch of claim 1, further comprising: an outer member extending perpendicular to a longitudinal length of the body member, the outer member including a finger pad.
 4. The bolt catch of claim 1, further comprising: a biasing member disposed in the void; wherein the body member is biased by the biasing member.
 5. The bolt catch of claim 4, wherein the biasing member has a pair of ends, with one end engaging the floor of the slot, and the other end engaging the body member.
 6. The bolt catch of claim 4, wherein the void includes a plurality of voids; and wherein the biasing member includes a plurality of biasing members, with each biasing member disposed in a respective void.
 7. The bolt catch of claim 4, wherein the void has a rounded edge to prevent the biasing member from binding to the body member.
 8. The bolt catch of claim 4, wherein the biasing member is selected from a compression spring, a torsion spring, and a magnet.
 9. A bolt catch for a firearm having a bolt, a slot with a floor, and a magazine for holding a cartridge, the bolt catch comprising: a body member dimensioned to be disposed within the slot, the body member having: a pair of opposing planar walls and a top planar wall, with the planar walls forming a parallelepiped-shaped void in the body member; and a pivot portion, wherein the body member is biased to rotate in a first rotational direction within the slot about the pivot portion, thereby blocking the bolt from moving forward; and an outer member extending perpendicular to a longitudinal length of the body member, the outer member including a finger pad for a user to press for rotating the body member in a second rotational direction opposite the first rotational direction and for countering the restorative force of the resilient member, thereby moving the bolt forward to engage the cartridge.
 10. The bolt catch of claim 9, wherein the pivot portion includes a hole for receiving a pivot pin.
 11. The bolt catch of claim 9, further comprising: a biasing member disposed in the void; wherein the body member is biased by the biasing member.
 12. The bolt catch of claim 11, wherein the biasing member has a pair of ends, with one end engaging the floor of the slot, and the other end engaging the body member.
 13. The bolt catch of claim 11, wherein the void includes a plurality of voids; and wherein the biasing member includes a plurality of biasing members, with each biasing member disposed in a respective void.
 14. The bolt catch of claim 11, wherein the void has a rounded edge to prevent the biasing member from binding to the body member.
 15. The bolt catch of claim 11, wherein the biasing member is selected from a compression spring, a torsion spring, and a magnet.
 16. A method for converting a semi-automatic firearm into a bolt action firearm, the semi-automatic firearm having a bolt, a slot with a floor, and a magazine for holding a cartridge, the method comprising: providing a bolt catch having a body member and an outer member extending perpendicular to a longitudinal length of the body member, the outer member including a finger pad, the body member dimensioned to be disposed within the slot, the body member having: a pair of opposing planar walls and a top planar wall, with the planar walls forming a parallelepiped-shaped void in the body member; and a pivot portion; positioning the body member within the slot; biasing the body member to rotate in a first rotational direction within the slot about the pivot portion, thereby blocking the bolt from moving forward; and pressing the finger pad to rotate the body member in a second rotational direction opposite the first rotational direction for countering the restorative force of the resilient member, thereby moving the bolt forward to engage the cartridge.
 17. The method of claim 16, wherein the bolt catch further comprises: a biasing member disposed in the void; wherein the body member is biased by the biasing member.
 18. The bolt catch of claim 17, wherein the biasing member has a pair of ends, with one end engaging the floor of the slot, and the other end engaging the body member.
 19. The method of claim 17, wherein the void includes a plurality of voids; and wherein the biasing member includes a plurality of biasing members, with each biasing member disposed in a respective void.
 20. The method of claim 17, wherein the biasing member is selected from a compression spring, a torsion spring, and a magnet.
 21. A firearm comprising: a lower receiver including a slot with a floor, wherein the floor has an aperture therein; a bolt catch disposed in the slot; and a biasing member including: a first end disposed in the aperture; and a second end engaging the bolt catch.
 22. The firearm of claim 21, wherein the biasing member is selected from a compression spring, a torsion spring, and a magnet.
 23. The firearm of claim 21, wherein the bolt catch has a lower surface facing the floor; and wherein the second end of the biasing member engages the lower surface of the bolt catch. 